[dubbo] branch 3.2 updated: Fix ClassPool issue when multi-classloader (#13015)

[albumenj]

This is an automated email from the ASF dual-hosted git repository.

albumenj pushed a commit to branch 3.2
in repository https://gitbox.apache.org/repos/asf/dubbo.git


The following commit(s) were added to refs/heads/3.2 by this push:
     new 6981a0f847 Fix ClassPool issue when multi-classloader (#13015)
6981a0f847 is described below

commit 6981a0f8473350d5867c3736b61455cd30e7a25c
Author: wien13 <veen...@gmail.com>
AuthorDate: Mon Sep 25 19:36:39 2023 +0800

    Fix ClassPool issue when multi-classloader (#13015)
---
 .../dubbo/common/bytecode/ClassGenerator.java      | 13 ++++++---
 .../org/apache/dubbo/common/bytecode/Wrapper.java  |  6 +---
 .../dubbo/common/bytecode/ClassGeneratorTest.java  | 33 ++++++++++++++++++++++
 3 files changed, 43 insertions(+), 9 deletions(-)

diff --git 
a/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/ClassGenerator.java
 
b/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/ClassGenerator.java
index b665c57075..f6a12df2ef 100644
--- 
a/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/ClassGenerator.java
+++ 
b/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/ClassGenerator.java
@@ -92,10 +92,15 @@ public final class ClassGenerator {
 
         ClassPool pool = POOL_MAP.get(loader);
         if (pool == null) {
-            pool = new ClassPool(true);
-            pool.insertClassPath(new LoaderClassPath(loader));
-            pool.insertClassPath(new DubboLoaderClassPath());
-            POOL_MAP.put(loader, pool);
+            synchronized (POOL_MAP) {
+                pool = POOL_MAP.get(loader);
+                if (pool == null) {
+                    pool = new ClassPool(true);
+                    pool.insertClassPath(new LoaderClassPath(loader));
+                    pool.insertClassPath(new DubboLoaderClassPath());
+                    POOL_MAP.put(loader, pool);
+                }
+            }
         }
         return pool;
     }
diff --git 
a/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/Wrapper.java 
b/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/Wrapper.java
index bde471afae..d5be038cb5 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/Wrapper.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/bytecode/Wrapper.java
@@ -22,8 +22,6 @@ import org.apache.dubbo.common.utils.ReflectUtils;
 
 import javassist.ClassPool;
 import javassist.CtMethod;
-import javassist.LoaderClassPath;
-
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -158,9 +156,7 @@ public abstract class Wrapper {
             pts.put(fn, ft);
         }
 
-        final ClassPool classPool = new ClassPool(ClassPool.getDefault());
-        classPool.insertClassPath(new LoaderClassPath(cl));
-        classPool.insertClassPath(new DubboLoaderClassPath());
+        final ClassPool classPool = ClassGenerator.getClassPool(cl);
 
         List<String> allMethod = new ArrayList<>();
         try {
diff --git 
a/dubbo-common/src/test/java/org/apache/dubbo/common/bytecode/ClassGeneratorTest.java
 
b/dubbo-common/src/test/java/org/apache/dubbo/common/bytecode/ClassGeneratorTest.java
index 607f6010c1..2eed4129aa 100644
--- 
a/dubbo-common/src/test/java/org/apache/dubbo/common/bytecode/ClassGeneratorTest.java
+++ 
b/dubbo-common/src/test/java/org/apache/dubbo/common/bytecode/ClassGeneratorTest.java
@@ -16,6 +16,7 @@
  */
 package org.apache.dubbo.common.bytecode;
 
+import javassist.ClassPool;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
@@ -23,6 +24,9 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
 
 interface Builder<T> {
     T getName(Bean bean);
@@ -197,6 +201,35 @@ class ClassGeneratorTest {
         builder.setName(b, "ok");
         System.out.println(b.getName());
     }
+
+    @Test
+    public void test_getClassPool() throws InterruptedException {
+        int threadCount = 5;
+        CountDownLatch LATCH = new CountDownLatch(threadCount);
+        ClassLoader loader = Thread.currentThread().getContextClassLoader();
+        List<Integer> hashCodeList = new ArrayList<>();
+        for (int i = 0; i < threadCount; i++) {
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    ClassPool classPool = ClassGenerator.getClassPool(loader);
+                    int currentHashCode = classPool.hashCode();
+                    hashCodeList.add(currentHashCode);
+                    System.out.println(currentHashCode);
+                    LATCH.countDown();
+                }
+            }).start();
+        }
+        LATCH.await();
+        Integer firstHashCode = null;
+        for (Integer currentHashCode : hashCodeList) {
+            if (firstHashCode == null) {
+                firstHashCode = currentHashCode;
+                continue;
+            }
+            Assertions.assertTrue(firstHashCode.intValue() == 
currentHashCode.intValue());
+        }
+    }
 }
 
 class Bean {